1. Field of the Invention
The invention relates to talking display signage, more particularly a display system that offers verbal annunciation utilizing digital record/playback with active infrared detection so as to interact with any target within a sensing range, as well as collection of statistical data during announcements.
2. Description of the Prior Art
Typically past devices used for similar purposes utilize passive detection systems. Hart, U.S. Pat. No. 4,930,236, and Hoshi, U.S. Pat. No. 4,934,079, disclose passive infrared detection devices, while Wu, U.S. Pat. No. 5,003,293 utilizes a heat radiation sensing element. The major disadvantage to these past inventions is that they require the target to emit or block energy, causing a change in energy to be detected by the sensor. This is known as passive detection. If the temperature of the target is the same as the ambient, no change in energy is detectable, such as in the case of a car fender, cat, bicycle, carriage, a heavily clothed person, or if the target enters the sensing area slowly. Since these devices sense a rate of change in energy within the viewing field, there would be no detection of the target. Carter, U.S. Pat. No. 3,088,996, uses available visible light optical interruption as a detection technique. This requires available visible light as a source to be interrupted by the target. This method is susceptible to variations in ambient light levels.